Wiper for drill pipes having a lubricant cavity



Sept. 23, 1952 J. BUCKLEY 2,511,146

WIPER FOR DRILL PIPES HAVING A LUBRICANT CAVITY Filed Dec. 20, 1947 IIIIIIIIIIIIIIII .ATT NEY Patented Sept. 23, 1952 rohannuekley-reaafl N. J.,- assignor to Unitedi; I

' States .ubb .Go na mw .York.. N Yea q e a eyfh w e 1 u sae'nneeember 20, 1th,; seri l negic'zjgcgfa (01:15 .210)...

V will .u .f This invention relates .toianimproved soft tic drill pipe wiper havingxspecialimeans embodied therein for retainingthe -mud ladened drilling fluid thewellcasing and for lubricat mg the sliding surfa'ce'of the drill pipe against the walls of the passage in the wiper-to reduce the wear on the wallsof the passage when the drill pipe is pulled out of: or goes intd-the well.

The'dri-ll pipe wiper embodying the present invention is adapted to be installedeini. the; usual manner above thetop ofthe'wellcasing, and below the .floo r of the rotarysturn-table which drives the drill pipe. However-,1 the-wiper maybeaattached to the rotary-table abovethesmasterbushe ing-as-xpreferredbv some drillersa..- H I The wiper comprises a bodyiwhichsisbrnade of softelastic wear-resis'tantrubber,, or rubber-like m'aterial having": a passage. extending-, there.- through for thereception. of .thadrill pipe on which. the mud-ladened-zfiuid is entrained upon being withdrawn ,from-r-the. well; .The improvement comprises a cavity formed in theirubber bodyparound.theaxisof the drill pipe passage which terminates in circular elastic lips adapted to fit under tension around. the pipe. The lips wipe. the mud-ladenedfluid, from. the pipe and collect and retain some of it inthe lcavity which acts as a lubricant between the sliding surfaces of the p pes nd' e l swhenzthe p p is pulled out ofthe well.

.Theiouter edges of such ,lipsare rounded to renderfthem resistant to weargena tear; and? the inside' edges' of the lips are provided with rela tivelyisquare edges which emei ntl remove .the mud-ladene'd drilling .fluidh m i the drill pipe and cause it tofiow'b'ack'i'n'to the well "casing. Some of the fluid is trapped in the cavity, while the excess flows back into the well between the rounded edge of the lower lip and the drill pipe. The trapped lubricating drilling fluid is available in the cavity to lubricate the drill pipe when it passes through the wiper. The coefiicient of resistance between the dry surfaces of the wiper and the pipe is relatively high and it is important that such surfaces be lubricated to reduce the friction.

The wiper has the further advantage of permitting the enlargements on the pipe, such as the Joints and protectors, if used, to pass with greater freedom through the wiper.

This invention is further described in connection with the accompanying drawings, in which:

Fig. 1 is a cross-sectional view of a drill pipe wiper embodying this invention, and shown in its. operative position on the drill pipe, which is b'eing -drawnefrom the-- we1l}throu'gh the rotary table'yw r 91 Figs- 2 is a cross-sectional view of the drili -pipe wiper in its normal 'molded 'shape priorto being placed over the drill pipe;- a'nd 9 I Fig. 3 is a plan view'of-la half-Section otgtl-ie -Th'e urn-1 pipe wiper m embodying-{this inventienis placed over the drillpipe-l tn usual man r, while the-pi-pe 1 issupportedentwined clamping slips (not shown) set the divided master bushing l Z c'arriedby thftfli'h table [3, which rotates ;the {pipe- I I In: such position -10! the pipe the ri'm o'f the als'eli'l'lrktl passage 1 4 i i-l the wiper is stretched-over the topoi-the; drill-pipe; The pipe I I is then supported the 'derrick ele vator, and is elevated" slightly to -permit the re"- moval: of the half-sections :ofthe clamping slips and master bushing .l2 The .wiper iii is 1 then pushed, or lowered @on the pipe- HI vbelowe tl'ie floor ofithe-turn table l3,l. and 'thezbushing' fl isxreplac'edimtheusual-mannersu The joinededri-ll pipe may thenbQ-lowerjed into .the? well casing .I 5 through tl leublowe outipreventor la. In the downward movementiofithe drill .pipe I i thewiper stops:..against. thesblowfe out; preventor I6; and upon L the withdrawal-slot the drill pipe the wiper. isustoppedaagainstzthe master bushing 12. In either dire'ctionofrlthe movementvof the drill pipe, H, its-.iointsul'l and the, usual rubber. protectors 18,1 if used ypass through the central passage orope'ning 14 in the wiper..l0..""'

The .wiper It comprises: a soft resilientiela'stic rubber body 19 having a centralpassagefli there in, which -termi-nates;.=at' each :side- Jof thei wiper iiisrelatively: thinrfi'exible elasticlips 20- which-fit tightly under the elastic tension of the rubber around the drill pipe II. The passage I4 is enlarged between the lips 20 for the purpose of forming an interior cavity 2| within the body [9 of the wiper Ill. The cavity surrounds the drill pipe II, and is sealed thereby when the wiper is applied thereto. The wiper I0 is molded in the shape shown in Fig. 2, and it has a reinforcing metal ring 22 incorporated therein. The cavity 2| is provided for the purpose of trapping the mud-laden or drilling fluid which is entrained on the pipe II when it is withdrawn from the casing l5. The lips 20 have rounded edges 23 on the outside surfaces of the wiper, and they are provided with relatively sharp square edges 24 on the inside of the wiper.

When the drill pipe II is withdrawn from the pipe casing I5 in the direction indicated by the arrow A in 1, the central portion of the wiper bends upwardly. The rounded edge 23 of. the bottom lip 20 removes most of the large abrasive particles from the drilling fluid and permits some of the fine lubricating mud to pass between the lips and the pipe into the lubricatin mud cavity 2| 1 The square edge 24 on the upper lip removes substantially all of the remaining mud from the surface of the pipe and causes it to be entrapped in the cavity 2|.

The rounded;

edges remove most of the abrasive material from. the mud-laden fluid before it enters the cavity 2 i,

and thereby protect the sharp square edges 24 from being abraded by it; I

The rounded edges 23 have the further advantage of increasing the tear resistance of the lips as well as protecting the less tear resistant square edges 24 from being torn by the passage through the lips of the pipe joints H or the protectors [8, J I

the pipe is lowered into the Well casing the dry mud tends to abrade theouter edge of the upper lip, but as the edge 23 first contacted is rounded, the abrasive effect is reduced, and the drymud ispermitt-ed to pass'through into; the interior cavity 2|. The dry surface of the pipe 1;]; becomes lubricated by the wet mud, or liquid in the cavity 2| before such surface reachesthe square edge 24 of the lower lip, which is then in contact with the pipe. The wall of the opening H in the wiper is thus protected against wear by the combination of the outer rounded edges Hand the inner sharp edges 24 of the lips.

The rubber body 19 of the wiper I0 should be made of a vulcanized rubber compound including natural or synthetic rubber having relatively high abrasion resistance and elastic qualities, and in some cases should have resistance to deterioration by oil. It has been found that a neoprene oil resisting compound containing the conventional fillers such as carbon black and having a 40 to 50 durometer hardness will operate successfully. Such compounds may be varied .to suit the conditions under which the wiper may be intended to operate.

While the'preferred embodiment of this'invention has been described and shown herein, it will f. 9,611,146 1111.: 1 J J;

be understood that the details may be changed without departing from the spirit of this invention or the scope of the appended claims.

Having thus described my invention, what I claim and desire to protect by Letters Patent is: 1. A drill pipe wiper comprising a unitary soft elastic body having a passage therethrough adapted to receive a drill pipe, said passage terminating at each end thereof in a relatively flexible elastic lip adapted to be stretched over enentrapped in: said enlarged portion.

' 2. A: drill pipe wiper comprising a unitary soft elastic body having a passage therethrough adapted to receive a drill pipe, said passage terminating at each end thereof in a relatively flexible elastic lip adapted to be stretched over en: largements on the pipe and fit snugly around the pipe, said passage having an enlargedportion between said lips, said enlarged portion, of; 'said passage being adapted to retain lubricating fluid therein, which may be removed from the advancing' pipe and be entrapped between said lips, each of said lips having. an outer rounded edge and an inner sharp edge, whereby said rounded edge of one lip is flexed againstthe advancing. surface of the'pip'e. to remove the m-ajor'portion of the lubricant in advance of said enlarged portion of the passage, and said sharp edge of the other lip is flexed against'the surfaceof thepipe receding from the last mentioned rounded edge to entrap the finer particles of the fluid in said enlarged portion.- r ornrp. BUCKLEYJ REFERENCES orrE The following references are of'record in the file of thispatent: V

UNITED STATES PATENTS 7 Date Number Name 445,569 Morningstar Feb. 3,189.1 v 1,641,921 Crowell Sept..6, 1927 1,823,233 Bell Sept. 15, 1931 2,147,250 Freeman Feb. '14, 1939 

